THURSDAY, Aug. 23 (HealthDay News) -- The increasing amount of time that people spend using computers, playing video games and watching TV is a major factor in rising rates of obesity worldwide, according to a new study.

The researchers at the Milken Institute in California found a direct link between spikes in adoption of new information and communications technology and the dramatic rise in obesity in 27 countries between 1988 and 2009.

The Milken Institute is an independent economic think tank.

"Technological innovations, more processed foods, a greater amount of 'screen time,' less exercise, and higher consumption of snack foods have all played a role," report co-author and economist Anusuya Chatterjee said in an institute news release. "These are all the adverse effects of a knowledge-based society."

More than 500 million adults worldwide are obese, according to background information in the news release. The United States has the highest percentage of obese adults (nearly 34 percent), followed by Mexico (30 percent), New Zealand (about 26 percent), Australia (nearly 25 percent) and Canada (just over 24 percent).

But obesity rates in many developing countries are also rising fast, the researchers noted. For example, the obesity rate in China more than doubled between 2002 and 2008, from 2.5 percent to 5.7 percent.

For their study, the Milken team looked at the effect that knowledge-based technology had on obesity rates in 27 countries that belong to the Organization for Economic Development and Cooperation. They did this by comparing the level of investment and communication technology (ICT) for each of the countries and their obesity rates.

For every 10 percent increase in ICT investment as a share of gross capital formation, the obesity rate climbed an average of 1.4 percent, the investigators found.

But the study authors also explained that in countries with high ICT investment rates, a 1 percent increase in the number of physically active people can prevent a 0.2 percent rise in obesity.

Overweight and obesity can lead to chronic diseases and disability, resulting in high human and economic costs for countries, and obesity is the fifth leading cause of death worldwide, the authors of the report pointed out.

"In addition to the human suffering, a key concern is the price tag. In the U.S., the medical burden of obesity climbed to 9.1 percent of annual medical spending in 2006 from 6.5 percent in 1998. Today, it is probably 12 percent and rising," concluded the report, published this month by the Milken Institute.